FaceTime Image Freezing

I FaceTime with my wife on a nightly basis and during every session the image on my MacBook Pro freezes. I can hear her and she can see/hear me but the image is frozen. All I have to do is move my curser and it unfreezes. Sometimes it will go a long time without freezing and other time it freezes every 10 seconds. Does anybody have any ideas as to a solution.